How do you feel about cracked spines?
No, not 'car accident' types. 'The text was too close to the spine so I had to wrench my book open' type.
I love and hate them.
I love them because they're undeniable proof that the reader loved the book and could barely contain themselves from reading more. I hate them because it means the text was too close to the gutter and the book interior designer didn't consider the binding when planning their layout.
The Good Ol' Days
Remember when most hardcovers had sewn bindings? Those days were nice, right? The book would lay (relatively) flat when you opened it. You could put it down without having to put much more than a simple paperweight on one side or the other.
Those days aren't gone, but they're not as prevalent as they were. These days there are a lot of ways to make a spine, and that means there are a lot of ways to handle the interior margins. Here are the most common we run into:
Perfect Bound (no signatures): Thick. Glued. Bindings. This is the most common binding style for all paperbacks, POD or print run. These bindings are tight. The tightest I've seen. I couldn't even get it to stay open without holding one side down.
These books need ample interior margins, or else you're going to be cracking spines all day. though, to be fair, POD always seems tighter than alternative printing methods. Usually, interior margins somewhere between .75, all the way to 1 inch will do, depending on how long the book is.
Perfect Bound (with signatures): Book printing traditionally uses batches of pages (called signatures), which would then get stapled or sewn together and then glued into a perfect bound book. The good news? They need less glue because the signatures are already stapled or sewn together. It's even holding itself open (well, mostly).
These aren't as tight as perfect bound, but they're pretty cozy. The difference is pretty damn serious. The top book (without signatures) is incredibly thick.
Meanwhile, the bottom book (with signatures), is a much more pleasant, thin glue job. Check it out:
Still glued: Signatures are glued (much more thinly than perfect bound) to a cloth spine, all of which is then wrapped by the hardcover case. Typically POD or cheaper press run printing. These actually lay open, but not completely flat. A solid middle ground, in my opinion. Interior margins only have to be moderately roomy. Probably .65 to .8 inches.
Sewn: Signatures are sewed to the cloth binding. The best of the best. Luxurious. Expensive. Only available in print runs. If you can work a few sweet Clevelands on these bad boys, you'll have some excellent hardcovers to sell to readers. Interior margins can be the tightest here. Sometimes as small as .25 to .5 inches.
My question to you is, how often do you have to force open a book when you're reading?
Are you one of those people who love the well-worn look, or is cracking a book spine about as painful as cracking your own?